After J&J, Eli Lilly stops antibody trials for COVID-19 over safety concerns

By Rahul Vaimal, Associate Editor
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A US government-sponsored clinical trial which was testing an antibody treatment for COVID-19 developed by drugmaker Eli Lilly has been stopped because of a ‘potential safety concern,’ says the company statement.

An antibody treatment stimulates the patient’s immune system to attack the foreign, infection causing cells.

The news comes just a day after Johnson & Johnson announced the paused of its coronavirus vaccine trial as a participant reported an ‘unexplained illness,’ and a month after AstraZeneca’s vaccine trial was stopped because of concerns about two participants who had fallen ill after receiving the vaccine from the company.

Read More: Creating herd Immunity by exposing to COVID-19 is unethical; WHO Chief

Safety concern

The Eli Lilly trial was equipped to test the effects of antibody therapy on hundreds of people hospitalized with COVID-19. Another experimental drug, ‘Remdesivir,’ which has been widely used for the treatment of coronavirus patients, was also given to all participants in the study. Exactly what safety concerns caused the pause is unknown.

Pauses are not unusual in large clinical studies and health declines in volunteers may not necessarily be the result of the experimental drug or vaccine. These pauses are intended to allow an impartial board of scientific experts to review the data and assess if the incident might have any link to the treatment or arose due to the treatment.

“This is why clinical trials are essential. The safety of the product has to be empirically proven,” says immunologists.

Enrollment for the Eli Lilly trial, funded by several divisions of the US National Institutes of Health (NIH) and the Department of Veterans Affairs, has been continuing. But last day, some officials sent emails to researchers asking them to stop adding volunteers to the study.

An NIH spokeswoman said in a statement that the trial, which enrolled 326 COVID-19 patients, was halted when the independent safety board noticed that the group of patients who received the antibodies displayed a different ‘clinical condition’ after five days of treatment than the group who received the placebo (the control in a drug experiment), a gap that crossed a predetermined safety threshold.

The NIH statement didn’t define the type of the conditions of the participants. But according to rules, a trial can be stopped when the treatment has a very low chance of working which is inferred based on the data. The trial may also be halted if there is evidence that patients in one group are faring significantly worse than those in the other.

On October 26, the safety board will again review the data and inform the NIH on whether to restart the trial, the statement said. In the meantime, data from people already participating in the study will continue to be collected by researchers.


As AstraZeneca and Johnson & Johnson have done with their vaccines, many experts praised the sponsors of the Eli Lilly trial for stopping the trial to examine the safety of their product.

In a statement sent over email, Molly McCully, a spokeswoman for Eli Lilly, confirmed the pause. “Safety is of the utmost importance to Lilly,” she said. “Lilly is supportive of the decision by the independent DSMB to cautiously ensure the safety of the patients participating in this study,” she added, referring to the independent panel of experts, known as the Data and Safety Monitoring Board.

How does Eli Lilly’s antibody treatment work?

Eli Lilly is one of several firms developing COVID-19 experimental treatments that use monoclonal antibodies, mass-generated mimics of immune molecules produced by the human body in response to the coronavirus.

The product of Eli Lilly is similar to the treatment designed by the US-based drug company Regeneron, which developed an antibody therapy administered to US President Trump after he tested coronavirus positive this month. Eli Lilly is also trialing its antibody treatment in people who have recently tested positive for the coronavirus and in nursing home residents and workers who may have been exposed.

Antibodies can block the coronavirus from infecting cells, and preliminary data from Eli Lilly and Regeneron have hinted that the immunity-mimicking treatments may be able to bring down the amount of virus in infected people and reduce their symptoms. Eli Lilly also hopes to gather data to find out if, even after encountering the virus, antibodies will prevent those individuals from developing COVID-19.